Glycolytic Oscillator

Selkov model variant — biochemical oscillations in glycolysis

Selkov model (1968)
dx/dt = α − βxy²
dy/dt = βxy² − y

x = ATP (substrate)
y = ADP (product/enzyme)

Oscillations exist when nullclines create an unstable fixed point. The system settles onto a limit cycle — sustained biochemical oscillations.

Nullclines shown:
red = dx/dt=0
blue = dy/dt=0